The E3 is supposed to be all about gaming, but since you can only go so far with realistic renderings of bullets entering and exiting various body parts, Microsoft's keynote was more about expanding the Xbox ecosystem - with, among other things, Internet Explorer and SmartGlass. The latter is a service which allows you to use additional devices - tablets, smrtphones, PCs - as remote controls for your Xbox. IT goes much further than that though, while watching a TV show or a game, SmartGlass can show additional content (i.e., a map of Westeros while watching Game of Thrones), or pick up content where you left off. Pretty cool - and coming to iOS and Android as well, including the game integration. Yup, expect Office for iOS and Android to land soon.

But, let me ask you this... besides the problem of not being built into the console (so less games will support it)

MS Kinect (kinda resolving separate controller issue here; it also kinda stole the spotlight from previous Nintendo console) is also like that, also coming very late in its console life cycle. And it became, IIRC, the fastest selling console peripheral ever; enjoying quite good support.